Compensated gyroscopic compass



`une 24 1924.

' 1,499,322 H. L. TNNER COMPENSATED GYROSCOPIC COMPASS Patent dune Zd, i924@ errel es este.

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CQMFENSATED @YROSCOPIG COMPASS.

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To all lwhom t may concern: Be it known that il, HARRY L. TANNm, a citizen of the United States of America, residing at 114:4@ East 19th Street, Brooki n, s in the county of Kings and State of l` ew York, have invented certain new and useful improvements in ompensated Gyroscopio Compasses, of which the following is a specication.y v ie This invention reiatesto gyroscopic coinpasses and especially to the type of gyro compass in which the directive element is not stabilized in all directions. it has been found that in such compasses errors arise la when the ship on which it is mounted is rolling on an intercardinal course. rlihe said errors may be said to be due to two diderent causes, to overcome the first of which it is the .object of the 'invention described in my 2o joint Letters Patent with Hannibal C. Ford, No. 1,273,799, dated Qluiy 23, 1918. The other source of error may be said to be due to centrifugal forces arising on the rolling and pitching in intercardinai planes, which 25 it is the ob'ect of this invention to overcome without the disadvantage of employing heavy auxiliary gyroscopes for stabilizing the apparatus.

Referring to the drawings in which what ao is now considered the preferred forni ofthe invention is shown: a

Fig. 1 is a we@ elevation, partly in section, of a gyroscopic compass of the Sperry type having my invention applied thereto. ss Fig. 2 is a south elevation of the rotor casing and attached parts, including the supporting rings, etc. with all parts thereof in section.

Fi 3 is la detail of the compensating no weig ts constituting the present embodiment of the invention.

Fig. l is a diagram illustrating the theory of the invention.

Referring to Fi. 4, this ligure represents es a weightless rod connecting two weights l and l and supported by a loop d and thread K from the pivot 0. lf the said weights are swung about the pivot in the plane of the loop or at right angles thereto s@ no torque will be exerted about the axis of the thread. lf' however, the, weights are swung in the plane at say 45 to the plane of the loop a torque will be exerted about the thread in such a direction as to turn the @s rod H and Weights l, l into the plane of oscillation., A similar phenomenon pr seats itself to an even more marked degree in the gyro compass as' will hereinafter he en plained. llt, however masses L sitioned at right angles l, ll the produced thereby wouldl balance torque due to i, ll and hence ne dedeeting would be produced.

ll have chosen for illustrating the invenf1 tion a standard Spewy compass of Battleship type, although it will readil; be understood that the invention is equaii" ap licable to all types of gyra-compass.,

eferring now to proper. The compass is shown as mounted within bowl l supported upon the standard 2 and suspended Within girnbal rines 3 d and a spider or main frame 5 within the bowl. The frame 5 rotatably supports in bearings and 1l, what is lrnovvn the Sperry compass as a follow-up element .S which is rotated by means of a motor actuated by reversing contacts (not shown) on the sensi tive and follow-up elements respectively. The sensitive element which includes the gyroscop-e itself is suspended from bearing 8 supported by a holiow stern 8 on the follow-up element. rIihe sensitive element comprises a vertical ring 9 which is directly suspended from bearing 8. The follow-up element is also provided with a ring 1'? connected tov stern 8 and which surrounds the aforesaid vertical ring and provides a lower guide bearing 18 Itherefor. The rotor casing proper 12 is supported on horizontal pivots 20 on the vertical ring preferably at or near its center of gravity. Pendulosity is iinparted to the casing in the embodiment shown by means of a yielding connection between the gyroscope and the follow-up frame comprising a heavy Weight or bail 21 which is suspended from the followup ring 17 on bearings 22 preferably in line With bearings 20 and is connected to the casing by a floating connection 23. Such connection in this instance comprises a pair of' rollers 24 one of which engages in a trac-k 25 on a casing and the other in a track 26 secured to the bail. Said rollers'are preferably secured to a pendulum having a long period in the E-`W plane such as ya small auxiliary gyroscopic pendulum'29 suspended at 29 from casing 19. Wit-hin the casing 19, the gyro rotor 28 is journalled onvhorizontal axes at right angles to the' axis 20. The rotor is I preferably electrically driven, forming the rotor of an induction motor the stator 31 of which is secured to the interior of the casing.

From the foregoing description it is apparent that the sensitive element including the vertical ring, gyro casing, rotor and attached parts comprise a pendulum oscillatable about the axes of thegimbal rings. The pendulum is peculiar, however,l when the gyroscope is running in that the entire rotor casing and rotor are stabilized about the axis 2O while about an axis at right angles thereto the parts are free to swing excepting only the rotor, the inning axis of which is parallel thereto. he effect of stabilizin the casing about axis 20 is to render su stantially ineffective the mass of the casing in the N-S plane. `In other words, referring to Fig. 4, if masses I, I and L, L were stabilized about axis I, I', masses L, L would have little or no effect and the torque due to I, I would predominate and cause deflection. Another way of looking at this is to consider that the stabilization of the casing about axis 2O in effect transfers the entire weight of the casing to the pivots 20 where the casing is su ported in the vertical ring 9. From thls it follows first that a 'marked torque will be exerted around the vertical axis, when the compass is oscillated in intercardinal lanes, second that any addition to the welght of the casing in the N--S plane will be ineffectual to overcome this torque, and third that to compensate for this torque much larger masses would have to be placed on either side of the axis 20 than would be necessary to merely equalize the moments of inertia of the casing and attached parts if the casing were not stabilized. It also follows that the rotor itself may be neglected since it is free about both horizontal axes, i. e. its spinning axis and axis 20.

` To overcome these difficulties I prefer to secure to the vertical ring 9 a plurality of masses 35 and 36 which are preferably suspended in line with the center of gravity of the casing and which lie beyond the confines of the case in the N-S direction.. Said masses as shown are preferably secured to curved bars 37 and 38 which extend underneathl the compass and are provided with lugs 39 and 40. Said lugs extend through openings 41 and 42 in the follow-up ring and are secured firmly to the vertical ring. The weight of the masses and their distance from the center of the casing is so adjusted that the couple exerted thereby about the rvertical axis on swinging .will balance the opposite couple due to the vertical ring and stabilized casing. As above pointed out this means that larger masses, or greater lever .arms for the masses must be used than if the plane. l

In order that the-masses maybe accurately positioned so that a erfect balance may be secured about both orizontal axes I prefer to mount each 'of them upon a The said i I tends is not concentric or through the center of gravity but to onesidethereof. Also clamp screws 46 andI 47 are preferably threaded radially through each mass to bear v upon the rod 40 and clamp the mass in any required position. By these various adjustments it will be readily seen that not only may the distance of the mass from the gyroscope casing be altered in the northsouth plane but also the center .of gravity thereof may be thrown slightly to one side or the other in the east-west plane so that the masses and gyroscope may be balanced in every plane with a minimum amount of adjustment.

A compass constructed according to my invention will not be disturbed in the least by swinging in any plane. The torques due to centrifugal forces, caused by the swinging in the arc of a. circle, which act on thestabilized casing, vertical ring, etc., are entirely balanced by the torques due to the compensating Weights 35 and 36 While the torques due to the pendulosity of the compass are eliminated by stabilizing the point of contact between the bail 21 and casing 19 by means of auxiliary gyro-pendulum 29.

While I prefer to employ a separate -means, i. e. an auxiliary gyroscope 29 and by the fact that the torque produced by both causes is in the same direction and su tantially proportionate in amount so that by increasing the moment of inertia of the gyroscope and frame in the N-S plane greatl 'beyond that of the same in the lane, the necessity for the iioating connectmn 'between the pendulous bail 21 anghthe gyro casing 19 is largely dispensed w1 In accordance with the provisions of the patent statutes, I have herein described the principle of operation of my invention, together with the apparatus, which I now con- Lacasse Sider to represent the best embodiment thereot, but l desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, While it is designed to use the various features elements in the combination and relations described, some of these may be altered and others omitted Without interfering with the more general results outiined, the invention extends nients of incr the N-S plane above 'that in the Tilwhen the rotor is not compensate for the stabilized gyrcseopic compass, the combinagyro-rotor and a casing thereical ring in which said casing `r is yournalled on a horizontal axis, means ior mounting said ring lor turning about a vertical axis, an arm secured to said ring and extending on both sides oir' said horizontal anis, seid being Weighted on each side sai 3, i a gvroseopic compass the combination with the gyro-rotor and a casing therefor, of a vertical ring in which said casing is journailed on a horizontal axis, means for mounting said ring for turning about a vertical axis, an arm secured to said ring and extending on both sides of said horizontal axis, said arm being Weighted on each side and in the horizontal plane of said axis.

in a gyroscopic compass, a support mounted for freedom about a plurality or' horizontal axes, a gyroscope pivoted to said support about/a horizontal axis and means rigidly secured to said support for equalizing the moment of the support and gyroscope while running in the N-S direction with that in the E-W direction. y

5. ln a gyroscopic compass, a support mounted for movement about a vertical axis, a gyroscope ivotally supported thereon and stabilized a out a horizontal axis and masses secured to said support having their center of gravity in a line at right angles to said horizontal axis and in substantially the same horizontal plane for increasing the moment in the N-S plane to substantially equal that of the stabilized gyroscope and support in the E--W plane. v

6. A. gyroscopic compass in which the gyroscope and its supporting parts are pendulously supported characterized by providing said parts with counterbalancing means such as weights so arranged as to increase the ballistic property or moments of inertia in the N-S direction above corresponding moments in the lil-JW direction when the rotor is not runnin-g. l l

7. ln a gyroseopic compass, the combination with gyroscope and a supporting frame therefor, of compensating Weights, a member supporting seid weights from said trarne and a mounting for said weights in said frame permitting adjustment of the centers of gravity thereof in a plurality of planes.,

8., ln a gyroscopic compass, the combination with a gyroscope and supporting frame therefor, or? compensating weights, a

member supporting said iveignts from saidl frame, a threaded shaft rotatably mounted in said member, one or" s weights being threaded thereon to side oi its center of gravit means whereby seid shaft be clamped any s tion the member and means whereby se, l 'weight may he clamped in any position on 9. in a gyroscop-ic compass, the combination with a gyroscope and a supporting frame therefor, of compensating Weights, a

member supper" .e is' weights from said frame, a threaact. rotatably mounted in said raf-einher, one -`weights being threaded thereon to side of its center o gravity, and f said weight may he in position on the shaft,

i0, ln a gyroscopic compass, the combination with a gyroscolse and a vsupporting trame therefor, of compensating weights, "a member supporting said Weights from said frame, a threaded shaft rotatably mounted in said member, one of said Weights beine threaded thereon, and ineens whereb said shait may be clamped in any position in the member. s

li. ln a gyroscopio compass, the combination with a gyroscope and a supporting frame therefor, of compensating Weights, a member supporting said Weights from said frame, a shaft mounted in said member and to which yone oi said weights ris adapted to be secured to one side of its center of gravity for adjustment either along or around the shaft.

12. in a gyroscopic compass, a support mounted for freedom about a plurality of horizontal axes, a gyroscope pivoted to said support about a horizontal axis, means secured to said support for equalizing the moment of the support and gyroscope in the N-S direction with that in the E--W direction, when running a pendulum for imparting pendulo'sity to the gyroscope, and means for stabilizing the pomt of connection between the pendulum and casing.

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13. In a gyroscopic compass comprisin a .tive gyroscope for stabilizing said connecl su port mounted for oscillation about a p utlon, and masses secured to said support on IQ ra `ty of horizontal axes, a directive oopposte sides of thedirective gyroscope for scope supported thereon for oscillation a ut e purpose specified. 5 a horizontal axis and turning about a verti- In' testimony whereof I have aliixed my.

cal axis, a yielding movable connection besignature.

tween said gyroscope and said support, an e f auxiliary gyroscope supported on said direcv HARRY L. TANNER. 

